[PATCH] powerpc: remove dead BIO_VMERGE_BOUNDARY definition

The block layer dropped the virtual merge feature
(b8b3e16cfe6435d961f6aaebcfd52a1ff2a988c5). BIO_VMERGE_BOUNDARY
definition is meaningless now (For POWER, BIO_VMERGE_BOUNDARY has been
meaningless for a long time since POWER disables the virtual merge
feature).

-/* We do NOT want virtual merging, it would put too much pressure on
- * our iommu allocator. Instead, we want drivers to be smart enough
- * to coalesce sglists that happen to have been mapped in a contiguous
- * way by the iommu
- */
-#define BIO_VMERGE_BOUNDARY 0
-
/*
* 32 bits still uses virt_to_bus() for it's implementation of DMA
* mappings se we have to keep it defined here. We also have some old
--
1.5.4.2